Organic semiconductors have been attracting attention as a semiconductor material taking the place of silicon and compound semiconductors. Production of semiconductor devices using conventional semiconductors necessarily involves high vacuum and high temperature processing operations, which has made cost reduction difficult. In contrast, use of organic semiconductor materials will make it feasible to produce semiconductor devices through a simple processing operation such as coating with a semiconductor solution or vacuum evaporation of the semiconductor material under room temperature conditions.
The inventors of the present invention previously found that a liquid crystal compound having a long linear conjugate structure and having a smectic phase as a liquid crystal phase develops excellent charge transport properties without requiring photoexcitation with a voltage applied while it is in a liquid phase of smectic phase or in a solid phase as a result of phase transfer from the smectic phase and proposed applying the liquid crystal compound to organic semiconductor devices, such as organic electroluminescent materials and thin film transistors (see, for example, Patent Document Nos. 1 to 5).    Patent Document 1: Japanese Patent Laid-Open publication No. 2004-6271    Patent Document 2: International Publication No. WO 2004/85360    Patent Document 3: International Publication No. WO 2004/85359    Patent Document 4: Japanese Patent Laid-Open publication No. 2004-311182    Patent Document 5: Japanese Patent Laid-Open publication No. 2005-142233